As a receptacle for coaxial connector used for transmission of a high-frequency signal, for example, Japanese Unexamined Patent Publication No. 2004-221055 (Patent Document 1) is disclosed. A structure thereof is described, based on FIG. 1.
This receptacle for coaxial connector 1 has an external conductor 10 having a cylindrical portion, and a central conductor 20 including a contact portion extending in an axis line direction in an internal space of the cylindrical portion, and is structured so as to integrally hold both the external conductor 10 and the central conductor 20 through a molded dielectric body (insulator) 30 in a lower section between both the conductors 10 and 20.
A lock groove 13 as a stopper of a plug is formed in the cylindrical portion of the external conductor 10. Further, in order to prevent the central conductor 20 from coming off from the dielectric body (insulator) 30 in a back surface direction by a stress at the time of plug attachment, a surface worked portion (recessed portion) 22A is provided in an inward end portion of the central conductor 20.
In a structure described in Patent Document 1, a resin is molded so as to cover an upper portion of the external conductor, and thus, a thickness of the external conductor and a thickness of the resin are accumulated, which increases outer dimensions of the product. Further, a position of the lock groove 13 provided in the cylindrical portion of the external conductor as the stopper of the plug becomes higher by the accumulated thickness of the resin, which also increases a whole height in a state where the plug is attached to the receptacle.
Furthermore, there is a problem that a distance between the lock groove 13 of the cylindrical portion of the external conductor 10 and an upper surface of the dielectric body (insulator) 30, which is a height needed to attach the plug, cannot be ensured.